MP240DEVELOPMENT OF AN “IN SITU” RENAL PERFUSION SYSTEM TO STUDY THE ORIGIN OF URINARY BIOMARKERS IN TWO ANIMAL MODELS OF ACUTE KIDNEY INJURY INDUCED BY GENTAMICIN AND ISCHEMIA-REPERFUSION

Abstract Background and Aims Diclofenac is frequently used for pain control. In a previous study, we showed that already a single oral dose of diclofenac could reduce renal perfusion in healthy individuals. To investigate the influence of oral diclofenac administration on renal inflammation in the setting of pre-existing renal damage, we used a mouse model of subclinical acute kidney injury (AKI) induced by renal ischemia-reperfusion injury (IRI) followed by diclofenac administration. Method Male CD1 mice (7-8 weeks old) underwent unilateral renal pedicle clamping for 15min to induce subclinical AKI. After reperfusion mice received a single oral dose of 100 or 200mg/kg diclofenac via oral gavage. Vehicle treated mice with unilateral IRI served as control. At day 1, mice were placed into metabolic cages to collect urine. Histology was performed on day 1 and 14 for renal morphology. Inflammation and fibrosis were investigated by immunohistochemistry and qPCR. Results Diclofenac treated mice showed reduced urine production. Morphologically, signs of AKI were more pronounced in diclofenac treated kidneys which also showed more Cox-2 positive tubuli in the cortex. On mRNA expression level the pro-inflammatory markers IL-6 and CXCL2, the chemoattractant for neutrophils, were elevated in the diclofenac group. Early upregulation of the pro-fibrotic markers CTGF and PAI-1 was detected already on d1 after IRI in the diclofenac group and tubular atrophy was pronounced after two weeks. Conclusion Already, a single oral dose of diclofenac causes aggravation of renal inflammation and progressive renal fibrosis in the setting of pre-existing subclinical acute kidney injury.

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Targeting acute kidney injury in COVID-19

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfaa231 ◽

2020 ◽

Vol 35 (10) ◽

pp. 1652-1662 ◽

Cited By ~ 3

Author(s):

John A Kellum ◽

J W Olivier van Till ◽

George Mulligan

Keyword(s):

Acute Kidney Injury ◽

Inflammatory Responses ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Renal Perfusion ◽

Endothelial Damage ◽

Acid Oxidation ◽

Acid Base ◽

The Impact ◽

Pathophysiologic Mechanisms

Abstract As of 15 August 2020, Coronavirus disease 2019 (COVID-19) has been reported in >21 million people world-wide and is responsible for more than 750,000 deaths. The occurrence of acute kidney injury (AKI) in patients hospitalized with COVID-19 has been reported to be as high as 43%. This is comparable to AKI in other forms of pneumonia requiring hospitalization, as well as in non-infectious conditions like cardiac surgery. The impact of AKI on COVID-19 outcomes is difficult to assess at present but, similar to other forms of sepsis, AKI is strongly associated with hospital mortality. Indeed, mortality is reported to be very low in COVID-19 patients without AKI. Given that AKI contributes to fluid and acid–base imbalances, compromises immune response and may impair resolution of inflammation, it seems likely that AKI contributes to mortality in these patients. The pathophysiologic mechanisms of AKI in COVID-19 are thought to be multifactorial including systemic immune and inflammatory responses induced by viral infection, systemic tissue hypoxia, reduced renal perfusion, endothelial damage and direct epithelial infection with Severe Acute Respiratory Syndrome Coronavirus 2. Mitochondria play a central role in the metabolic deregulation in the adaptive response to the systemic inflammation and are also found to be vital in response to both direct viral damage and tissue reperfusion. These stress conditions are associated with increased glycolysis and reduced fatty acid oxidation. Thus, there is a strong rationale to target AKI for therapy in COVID-19. Furthermore, many approaches that have been developed for other etiologies of AKI such as sepsis, inflammation and ischemia–reperfusion, have relevance in the treatment of COVID-19 AKI and could be rapidly pivoted to this new disease.

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Early antihypertensive treatment and ischemia-induced acute kidney injury

AJP Renal Physiology ◽

10.1152/ajprenal.00078.2020 ◽

2020 ◽

Vol 319 (4) ◽

pp. F563-F570

Author(s):

Robert Greite ◽

Katja Derlin ◽

Bennet Hensen ◽

Anja Thorenz ◽

Song Rong ◽

...

Keyword(s):

Blood Pressure ◽

Acute Kidney Injury ◽

Antihypertensive Treatment ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Renal Perfusion ◽

Renal Outcome ◽

Major Surgery ◽

Mesangial Matrix ◽

Matrix Expansion

Acute kidney injury (AKI) frequently complicates major surgery and can be associated with hypertension and progress to chronic kidney disease, but reports on blood pressure normalization in AKI are conflicting. In the present study, we investigated the effects of an angiotensin-converting enzyme inhibitor, enalapril, and a soluble epoxide hydrolase inhibitor, 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl)urea (TPPU), on renal inflammation, fibrosis, and glomerulosclerosis in a mouse model of ischemia-reperfusion injury (IRI)-induced AKI. Male CD1 mice underwent unilateral IRI for 35 min. Blood pressure was measured by tail cuff, and mesangial matrix expansion was quantified on methenamine silver-stained sections. Renal perfusion was assessed by functional MRI in vehicle- and TPPU-treated mice. Immunohistochemistry was performed to study the severity of AKI and inflammation. Leukocyte subsets were analyzed by flow cytometry, and proinflammatory cytokines were analyzed by quantitative PCR. Plasma and tissue levels of TPPU and lipid mediators were analyzed by liquid chromatography mass spectrometry. IRI resulted in a blood pressure increase of 20 mmHg in the vehicle-treated group. TPPU and enalapril normalized blood pressure and reduced mesangial matrix expansion. However, inflammation and progressive renal fibrosis were severe in all groups. TPPU further reduced renal perfusion on days 1 and 14. In conclusion, early antihypertensive treatment worsened renal outcome after AKI by further reducing renal perfusion despite reduced glomerulosclerosis.

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Impaired Tubular Reabsorption Is the Main Mechanism Explaining Increases in Urinary NGAL Excretion Following Acute Kidney Injury in Rats

Toxicological Sciences ◽

10.1093/toxsci/kfaa029 ◽

2020 ◽

Vol 175 (1) ◽

pp. 75-86 ◽

Cited By ~ 1

Author(s):

Sandra M Sancho-Martínez ◽

Víctor Blanco-Gozalo ◽

Yaremi Quiros ◽

Laura Prieto-García ◽

María J Montero-Gómez ◽

...

Keyword(s):

Acute Kidney Injury ◽

Ischemia Reperfusion Injury ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Renal Perfusion ◽

Tubular Reabsorption ◽

Urinary Ngal ◽

Neutrophil Gelatinase Associated Lipocalin ◽

Perfusion Studies ◽

Glomerular Filtrate

Abstract Neutrophil gelatinase-associated lipocalin (NGAL) is a secreted low-molecular weight iron-siderophore-binding protein. NGAL overexpression in injured tubular epithelia partly explains its utility as a sensitive and early urinary biomarker of acute kidney injury (AKI). Herein, we extend mechanistic insights into the source and kinetics of urinary NGAL excretion in experimental AKI. Three models of experimental AKI were undertaken in adult male Wistar rats; renal ischemia-reperfusion injury (IRI) and gentamicin (G) and cisplatin (Cisp) nephrotoxicity. Alongside standard histological and biochemical assessment of AKI, urinary NGAL excretion rate, plasma NGAL concentration, and renal NGAL mRNA/protein expression were assessed. In situ renal perfusion studies were undertaken to discriminate direct shedding of NGAL to the urine from addition of NGAL to the urine secondary to alterations in the tubular handling of glomerular filtrate-derived protein. Renal NGAL expression and urinary excretion increased in experimental AKI. In acute studies in both the IRI and G models, direct renal perfusion with Kreb’s buffer eliminated urinary NGAL excretion. Addition of exogenous NGAL to the Kreb’s buffer circuit, reestablishment of perfusion with systemic blood or reperfusion with renal vein effluent restored high levels of urinary NGAL excretion. Urinary NGAL excretion in AKI arises in large proportion from reduced reabsorption from the glomerular filtrate. Hence, subclinical cellular dysfunction could increase urinary NGAL, particularly in concert with elevations in circulating prerenal NGAL and/or pharmacological inhibition of tubular reabsorption. More granular interpretation of urinary NGAL measurements could optimize the scope of its clinical utility as a biomarker of AKI.

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Identification of Hub Genes Associated with the Development of Acute Kidney Injury by Weighted Gene Co-Expression Network Analysis

Kidney & Blood Pressure Research ◽

10.1159/000511661 ◽

2021 ◽

pp. 1-11

Author(s):

Xiao Lin ◽

Jianchun Li ◽

Ruizhi Tan ◽

Xia Zhong ◽

Jieke Yang ◽

...

Keyword(s):

Acute Kidney Injury ◽

Network Analysis ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Clinical Syndrome ◽

Hub Genes ◽

Tissue Fluorescence ◽

Agent Development ◽

Geo Database

Background: Acute kidney injury (AKI) is a severe clinical syndrome, causing a profound medical and socioeconomic burden worldwide. This study aimed to explore underlying molecular targets related to the progression of AKI. Methods: A public database originated from the NCBI GEO database (serial number: GSE121190) and a well-established and unbiased method of weighted gene co-expression network analysis (WGCNA) to identify hub genes and potential pathways were used. Furthermore, the unbiased hub genes were validated in 2 classic models of AKI in a rodent model: chemically established AKI by cisplatin- and ischemia reperfusion-induced AKI. Results: A total of 17 modules were finally obtained by the unbiased method of WGCNA, where the genes in turquoise module displayed strong correlation with the development of AKI. In addition, the results of gene ontology revealed that the genes in turquoise module were involved in renal injury and renal fibrosis. Thus, the hub genes were further validated by experimental methods and primarily obtained Rplp1 and Lgals1 as key candidate genes related to the progression of AKI by the advantage of quantitative PCR, Western blotting, and in situ tissue fluorescence. Importantly, the expression of Rplp1 and Lgals1 at the protein level showed positive correlation with renal function, including serum Cr and BUN. Conclusions: By the advantage of unbiased bioinformatic method and consequent experimental verification, this study lays the foundation basis for the pathogenesis and therapeutic agent development of AKI.

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MO468NEW URINARY BIOMARKERS DETECT SUBCLINICAL RENAL DAMAGE AFTER SEVERAL ACUTE KIDNEY INJURY EPISODES

Nephrology Dialysis Transplantation ◽

10.1093/ndt/gfab090.0030 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

Giampiero A Massaro ◽

Joana Mercado-Hernandez ◽

Ana Carbajo-Uña ◽

Isabel Fuentes-Calvo ◽

Sandra M Sancho Martinez ◽

...

Keyword(s):

Acute Kidney Injury ◽

Renal Function ◽

Ischemia Reperfusion ◽

Left Kidney ◽

Kidney Injury ◽

Renal Ischemia ◽

Urinary Biomarkers ◽

Control Group ◽

Clinical Parameters ◽

Group 5

Abstract Background and Aims Acute kidney injury (AKI) represents a clinical problem due to its increasing prevalence and association with further morbidities. Observational studies have shown that AKI increases the risk of a new AKI episode, chronic kidney disease (CKD), CKD progression, end-stage renal disease (ESRD), and mortality. Serum creatinine (sCr) is the parameter most used by clinicians for determining AKI and the subsequent recovery, however its use presents several limitations. sCr lacks sensitivity for AKI and provides minimal insight into the renal structure. Indeed, increases in sCr are observed only when glomerular filtration rate decreases more than 50%. Therefore, new markers need to be identified to predict recovery after AKI and to detect residual structural alterations that can cause progression to CKD. We hypothesised that after AKI, there are renal structural abnormalities that cannot be detected by common clinical parameters but may be detected by urinary biomarkers. Method We used 4 weeks old male Wistar rats. Animals were divided into 5 experimental groups: Control group: SHAM operated rats, saline solution i.p.; “CDDP5-SHAM” group: 5 mg/kg cisplatin i.p.; “Ctrl-I/R60” group: 60-minute renal ischemia reperfusion in the left kidney; “CDDP5-I/R60” group: 5 mg/kg cisplatin i.p. and after renal function normalization, 60-minute ischemia-reperfusion (I/R60); “5/6 NEF” group: 5/6 nephrectomy. Blood and urine were collected at: day 0 (basal); day 4 (AKI development); day 8 (normalized renal function after AKI and induction of renal ischemia); day 9 (1 day after ischemia); day 13, day 20 and every week thereafter. Renal function was analyzed by sCr, creatinine clearance, blood urea nitrogen and proteinuria determination using colorimetric methods. Urinary biomarkers were analyzed at day 20 (12 days after the second damage and 20 after the first one) by western blot and ELISA. Animals were sacrificed at the same time point in which urinary biomarkers were determined, and renal tissue samples were stained with Masson´s trichrome, Sirius Red and Periodic Acid-Schiff for histological analysis. Results Frequency of AKI episodes is related to the amount and degree of subclinical alterations detected in the kidneys, even though renal filtration is apparently normal. We characterized a novel panel of urinary biomarkers (bk1-bk4) several days after the last insult (day 20) when renal function appeared normal; these biomarkers were present in highest concentrations in the CDDP5-I/R60 experimental group. Conclusion These results demonstrate the importance of the clinical implementation of biomarkers as useful tools for medical support and underline the limitations of the clinical parameters (e.g. sCr, estimated GFR) currently used for renal function assessment. The frequency of AKI episodes is related to a poor prognosis, so a follow up is necessary after AKI episodes in order to prevent mortality and progression of the disease.

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Renoprotective Effects of DNAse-I Treatment in a Rat Model of Ischemia/Reperfusion-Induced Acute Kidney Injury

American Journal of Nephrology ◽

10.1159/000445546 ◽

2016 ◽

Vol 43 (3) ◽

pp. 195-205 ◽

Cited By ~ 16

Author(s):

Victoria Peer ◽

Ramzia Abu Hamad ◽

Sylvia Berman ◽

Shai Efrati

Keyword(s):

Acute Kidney Injury ◽

Inflammatory Diseases ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Treated Group ◽

Renal Perfusion ◽

Dnase I ◽

Sprague Dawley ◽

Contralateral Kidney ◽

Debris Accumulation

Background: Massive DNA destruction/accumulation of cell-free DNA debris is a sensitive biomarker of progressive organ/tissue damage. Deleterious consequences of DNA debris accumulation are evident in cardiac ischemia, thrombosis, auto-inflammatory diseases, SLE-induced lupus nephritis and cystic fibrosis. In case of renal pathologies, degradation and elimination of DNA debris are suppressed, due to downregulated DNAse-I activity within the diseased kidneys. The aim of the current study was to evaluate whether exogenous DNAse-I administration might exert renoprotective effects in the setting of acute kidney injury (AKI or acute renal failure). Methods: Sprague-Dawley rats underwent unilateral nephrectomy, with simultaneous clamping of contralateral kidney artery. The treated group received DNAse-I injection before discontinuing anesthesia. Positive (ischemic) controls received saline injection. Negative (non-ischemic) controls were either non-operated or subjected to surgery of similar duress and duration without ischemia. Renal perfusion was evaluated using the Laser-Doppler technique. Blood was procured for evaluating DNAse-I activity, renal functioning, renal perfusion. The kidneys were allocated for histopathologic examinations and for the evaluation of renal hypoxia, intra-renal apoptosis and proliferation. Results: Contrary to the situation in untreated ischemic rats, renal perfusion was significantly improved in DNAse-treated animals, concomitantly with significant amelioration of damage to renal functioning and tissue integrity. Treatment with DNAse-I significantly decreased the ischemia-induced renal hypoxia and apoptosis, simultaneously stimulating renal cell proliferation. Exogenous DNAse-I administration accelerated the clearance of intra-renal apoptotic DNA debris. Conclusion: Functional/histologic hallmarks of renal injury were ameliorated, renal functioning improved, intra-renal hypoxia decreased and intra-renal regeneration processes were activated. Thus, DNAse-I treatment protected the kidney from deleterious consequences of ischemia-induced AKI.

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The Efficacy of Mesenchymal Stem Cells in Therapy of Acute Kidney Injury Induced by Ischemia-Reperfusion in Animal Models

Stem Cells International ◽

10.1155/2020/1873921 ◽

2020 ◽

Vol 2020 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Tianbiao Zhou ◽

Chunling Liao ◽

Shujun Lin ◽

Wenshan Lin ◽

Hongzhen Zhong ◽

...

Keyword(s):

Stem Cells ◽

Acute Kidney Injury ◽

Mesenchymal Stem Cells ◽

Animal Models ◽

Ischemia Reperfusion ◽

Meta Analysis ◽

Cochrane Review ◽

Kidney Injury ◽

Cochrane Library ◽

Differentiation Potential

Mesenchymal stem cells (MSCs), discovered and isolated from the bone marrow in the 1960s and with self-renewal capacity and multilineage differentiation potential, have valuable immunomodulatory abilities. Acute kidney injury (AKI) refers to rapid renal failure, which exhibits as quickly progressive decreasing excretion in few hours or days. This study was performed to assess the efficacy of MSCs in the treatment of AKI induced by ischemia-reperfusion using a meta-analysis method. A literature search using corresponding terms was performed in the following databases: Embase, Cochrane Library, PubMed, and ISI Web of Science databases up to Dec 31, 2019. Data for outcomes were identified, and the efficacy of MSCs for AKI was assessed using Cochrane Review Manager Version 5.3. Nineteen studies were eligible and recruited for this meta-analysis. MSC treatment can reduce the Scr levels at 1 day, 2 days, 3 days, 5 days, and >7 days (1 day: WMD=−0.56, 95% CI: -0.78, -0.34, P<0.00001; 2 days: WMD=−0.58, 95% CI: -0.89, -0.28, P=0.0002; 3 days: WMD=−0.65, 95% CI: -0.84, -0.45, P<0.00001; 5 days: WMD=−0.35, 95% CI: -0.54, -0.16, P=0.0003; and >7 days: WMD=−0.22, 95% CI: -0.36, -0.08, P=0.002) and can reduce the levels of BUN at 1 day, 2 days, 3 days, and 5 days (1 day: WMD=−11.72, 95% CI: -18.80, -4.64, P=0.001; 2 days: WMD=−33.60, 95% CI: -40.15, -27.05, P<0.00001; 3 days: WMD=−21.14, 95% CI: -26.15, -16.14, P<0.00001; and 5 days: WMD=−8.88, 95% CI: -11.06, -6.69, P<0.00001), and it also can reduce the levels of proteinuria at 3 days and >7 days and alleviate the renal damage in animal models of AKI. In conclusion, MSCs might be a promising therapeutic agent for AKI induced by ischemia-reperfusion.

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Porcine Models of Acute Kidney Injury

AJP Renal Physiology ◽

10.1152/ajprenal.00022.2021 ◽

2021 ◽

Author(s):

Jianni Huang ◽

George P Bayliss ◽

Shougang Zhuang

Keyword(s):

Acute Kidney Injury ◽

Body Size ◽

Animal Models ◽

Medical Research ◽

Ischemia Reperfusion ◽

Kidney Injury ◽

Comprehensive Overview ◽

Advantages And Disadvantages ◽

Primary Focus ◽

Similar Body

Pigs represent a potentially attractive model for medical research. Similar body size and physiological patterns of kidney injury that more closely mimic those described in humans make larger animals attractive for experimentation. Using larger animals, including pigs, to investigate the pathogenesis of acute kidney injury (AKI) also serves as an experimental bridge, narrowing the gap between clinical disease and preclinical discoveries. This article compares the advantages and disadvantages of large versus small AKI animal models and provides a comprehensive overview of the development and application of porcine models of AKI induced by clinically relevant insults, including ischemia/reperfusion, sepsis and nephrotoxin exposure. The primary focus of this review is to evaluate the use of pigs for AKI studies by current investigators, including areas where more information is needed.

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Development of an “In Situ” renal perfusion system to study the origin of urinary biomarkers in a nephrotoxicity model induced by gentamicin

European Journal of Molecular & Clinical Medicine ◽

10.1016/j.nhtm.2014.11.055 ◽

2015 ◽

Vol 2 (2) ◽

pp. 71

Author(s):

Francisco J. López-Hernández ◽

Blanco-Gozalo V. ◽

L. Prieto-García ◽

S.M. Sancho-Martínez ◽

J.M López-Novoa

Keyword(s):

Renal Perfusion ◽

Urinary Biomarkers ◽

Perfusion System

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